The basics

Famine, Affluence, and Morality - Peter Singer
Written in 1971, this essay has inspired numerous effective altruists. Singer argues that we have a moral obligation to give a significant portion of our resources to help people poorer than ourselves.

The Life You Can Save - Peter Singer
Singer wrote The Life You Can Save to show that our current response to world poverty is not only insufficient but ethically indefensible. He argues that we need to change our views of what is involved in living an ethical life. To help us play our part in bringing about that change, he offers a seven-point plan that mixes personal philanthropy (figuring how much to give and how best to give it), local activism (spreading the word in your community), and political awareness (contacting your representatives to ensure that your nation’s foreign aid is really directed to the world’s poorest people).

Poverty

Poor Economics - Abhijit Banerjee and Esther Duflo
Tells which choices poor people actually make and what really helps to alleviate poverty (it's evidence based, unlike a lot of other ideological books on poverty).

Scarcity: Why Having Too Little Means So Much - Sendhil Mullainathan and Eldar Shafir
It's about how scarcity affects you psychologically and why people suffering from it (e.g. poor people or people with a high work load) make "irrational" choices.

Living High and Letting Die: Our Illusion of Innocence - Peter Unger
Features many thought experiments trying to establish that our moral obligations to relieving poverty are not lessened by the commonly proposed reasons. Unger argues we have a moral obligation to do absolutely everything in our power to help the impoverished.

World Poverty and Human Rights - Thomas Pogge
Pogge analyses how our moral and economic theorizing and our global economic order have adapted to make us appear disconnected from massive poverty abroad. Dispelling the illusion, he also offers a modest, widely sharable standard of global economic justice and makes detailed, realistic proposals toward fulfilling it.

Future generations

Global Catastrophic Risks - ed. by Nick Bostrom and Milan Cirkovic
A global catastrophic risk is one with the potential to wreak death and destruction on a global scale. In this book 25 leading experts look at the gravest risks facing humanity in the 21st century, including asteroid impacts, gamma-ray bursts, Earth-based natural catastrophes, nuclear war, terrorism, global warming, biological weapons, totalitarianism, advanced nanotechnology, general artificial intelligence, and social collapse. The book also addresses overarching issues - policy responses and methods for predicting and managing catastrophes.

Animal welfare

All Animals Are Equal - Peter Singer
Argues that, in deciding what to do, we should we the interests of non-human animals as much weight as the interests of members of our own species.

Improving your thinking

Thinking, Fast and Slow - Daniel Kahneman
Contains profound scientific insights into how humans think, make decisions and experience happiness or pain. There is almost nothing in the book that can't be related to Effective Altruism or acted upon by Effective Altruists themselves.

How To Measure Anything - Douglas Hubbard
An overview of how to make good estimations and measurements. Presents a clear discussion of Expect Value of Information and Uncertainty Calibration, which are very useful when making strategic decisions about life and organization decisions. A very nice summary by Luke Muehlhauser is here.

Career and business

So Good They Can't Ignore You - Cal Newport
The best popular career-strategy book we've come across. Newport argues that 'follow your passion' is bad advice, and that the systematic development of rare and valuable skills is far more important. He also provides some useful principles for making career decisions.

Handbook of Principles of Organizational Behaviour - ed by Edwin Locke
Most business advice isn't evidence-based - this book gives practical advice on topics in business and management, backed up by the best evidence. It is used extensively in 80,000 Hours to help with career research. Topics include: causes of career success, improving motivation, job satisfaction, leadership, effective training, goal setting, and much more.

Never Eat Alone - Keith Ferrazzi and Tahl Raz
Networking is important for career success. Never Eat Alone gives practical advice on how to network effectively without being sleazy.

The Lean Startup - Eric Ries and Four Steps to the Epiphany - Steven Blank
When you're starting an organisation (or planning your career) it's tempting to come up with an idea and then just work towards making it happen. The risk is then that you make something that no-one wants. The lean startup movement provides an alternative - as you set up your company you should be testing hypotheses and changing plans as you get more information. These two books have become widely used in tech startups. The Lean Startup is good as an introduction, and Four Steps to the Epiphany contains a detailed step-by-step process for actually doing it. A nice additional benefit is that you can use the same method for planning your career.

Influence: The Psychology of Persuasion - Robert Cialdini
Classic evidence-based book on how people are persuaded of things. Useful both for persuading others and watching out for when you might be being manipulated.

The Charisma Myth - Olivia Fox Cabane
Most people believe that charisma can’t be learnt - you either have it or you don’t. This book shows you why that isn’t true and how to learn it, including practical exercises on how to become more charismatic.

The Copywriter’s Handbook - Robert Bly
For anyone who needs to persuade people with writing, this is a classic practical guide.

Productivity

Getting Things Done - David Allen
Getting things done (GTD) provides a task management system which will help you to be more organised and less stressed. It's probably the most popular task management system, and is being used by lots of EAs.